In response to the Dissemination and Implementation Research in Health PAR 10-38, we propose to examine the integration of two evidence-based tobacco treatments into real-world cancer care settings. Quitting smoking after cancer diagnosis may increase patients' quality of life and improve treatment outcomes through decreases in complications from surgery, radiation or chemotherapy, and decreases in risk of second primary tumors. At diagnosis, approximately 10-30% of cancer patients are smokers, and many have elevated socioeconomic, biologic, and psychosocial vulnerabilities. The U.S. Department of Health and Human Services Public Health Service has evidence-based tobacco treatment guidelines, but these have not been integrated into cancer care. An American Society of Clinical Oncology core quality indicator is identification, advice, and counseling of all smokers by their second cancer visit, but these quality standards are not being met. To address this treatment gap, we propose to conduct the first comparative effectiveness trial to assess the effectiveness of two evidence-based tobacco treatments among newly diagnosed cancer patients. Our proposal is guided by Dr. Park's findings from a nonrandomized controlled pilot study (5R03CA130722-02) which showed promising feasibility and efficacy for delivering an evidence-based Intensive Treatment (IT) to newly diagnosed lung cancer patients at Massachusetts General Hospital (MGH). We propose to enroll 295 current smokers newly diagnosed with lung, colon, breast, or prostate cancer (the four most prevalent cancers) at MGH and Memorial Sloan Kettering Cancer Center (MSK) and compare the differential effectiveness of delivering an Intensive Treatment (IT; 10 motivational counseling sessions plus 12 weeks of FDA approved smoking cessation medication) versus a Brief Treatment (BT; the current treatment provided at MSK, which is 4 motivational counseling sessions plus medication advice). Aim 1 will compare the effectiveness of the two tobacco treatments in promoting biochemically confirmed tobacco abstinence at 6 months. Aim 2 will assess mechanisms through which treatment promotes abstinence, subpopulations in which abstinence is promoted, and aspects of treatment that promote abstinence. Aim 3 will explore how many smokers enroll in, and adhere to, tobacco treatment. This proposal is unique in its 1) theory [(combining a chronic illness (Self-Regulation) and behavior change (Health Belief) model)], 2) integrated tobacco treatments (targeted to patients undergoing cancer treatment), and 3) collaborative care model (sustainable and facilitated through state-of- the art electronic health record systems). Study findings will addres previously unanswered questions about provision of integrated tobacco treatment as part of comprehensive cancer care. Furthermore, it will provide information to lay the groundwork for dissemination efforts into a variety of cancer care settings.